1. Field of the Invention
This invention relates to an image projecting apparatus as for the reader-printer which is used for projecting information recorded in a microfilm on a screen and printing the information on a copying paper.
2. Description of the Prior Art
For the purpose of reducing the width of the main body or housing of the reader-printer and, at the same time, improving the operability of the reader-printer, a reader-printer of the so-called front-face paper-discharging type which discharges a printed copying paper through the front face of the housing has been developed (U.S. Pat. No. 4,885,605).
In recent years, there are times when individual image frames are recorded widthwise in the microfilm which is loaded in the reader-printer. In the COM type microfilm, i.e. a microfilm of the type having information recorded therein by the use of a computer, for example, information is often recorded widthwise in each of the frames. When the information recorded in the microfilm of this kind is projected on a screen, it lands on the screen widthwise, namely the longer side of the frame falls horizontally and the shorter side thereof vertically. When the recorded information is to be printed on a copying paper, the reader-printer disclosed in the U.S. patent mentioned above is so adapted that the recorded information is projected on a photosensitive medium as scanned in the vertical direction of the image shown on the screen, namely in the direction along the shorter side of the image frame. The conventional reader-printer, therefore, requires to incorporate in the image forming part thereof with a photosensitive drum possessing a length equaling the longer side mentioned above.
When the reader-printer is adapted to project a given image recorded in a microfilm on a photosensitive medium while scanning that image in the direction along the longer side of the frame of the image for the purpose of printing the image on a copying paper, it is made possible to allot to the length of the photosensitive drum a size equaling the length of the shorter side and not the longer side of the copying paper and consequently reduce the length of the photosensitive drum. For the purpose of this adaptation, however, the recorded information must be turned 90 degrees from the posture allowing the information to be projected on the screen to the posture allowing the information to be projected on the photosensitive drum. Therefore, a rotary drive mechanism incorporating therein a prism has been used in a projecting lens for enabling the image frame to be projected on the photosensitive drum to be turned 90 degrees as described above. The use of the projecting lens which incorporates the rotary drive mechanism of this description therein, however, results in an increase in the cost of the reader-printer.
U.S. Pat. No 4,885,605 mentioned above discloses a reader-printer which is provided with a mirror 28 for scanning a microfilm in the direction along the longer side of an image frame, a mirror 36 for reflecting backwardly the reflected light from the mirror 28, and a mirror 38 adapted to move synchronously with the mirror 28 and reflect the reflected light from the mirror 36 toward a photosensitive material 34.
Incidentally, in this reader-printer, since the two mirrors 28, 38 must be correlatively moved, these mirrors 28, 38 must be positioned with high accuracy. The high accuracy required for the positioning is difficult to attain and certain to entail an increase in the cost of production.
An object of this invention, therefore, is to provide a small image projecting apparatus which is capable of turning an image frame 90 degrees without requiring incorporation of a rotary mechanism in a projecting lens.
Another object of this invention is to provide an image projecting apparatus which allows easy positioning of mirrors and entails no increase in the cost of production.
In accordance with the present invention there is provided, an image projecting apparatus, comprising projecting means for projecting the light through an image recorded in a microfilm on a first surface for receiving the projected light, light path changing means adapted to thrust into the projected light path and alter said light path, reflecting means for causing the image light the path of which has been altered by said light path changing means to be reflected toward a twisted position relative to the path for an incident light toward said light path changing means and made to impinge on a second surface for receiving said ident light, and moving means for selectively moving said light path changing means to a position allowing said light path changing means to thrust into the light path of said projecting means and a position allowing said light path changing means to retract from said light path of said projecting means.